Ventilation damper for air conditioning apparatus

ABSTRACT

A ventilation damper for a unitary air conditioner wherein a partition separates the area to be cooled from ambient. An interconnecting aperture in the partition permits outside air to be conveyed into the area to be cooled. A damper mechanism or door normally closing the aperture opens in operative response to a flow of external air produced by a fan or blower. The air flow may be provided by the same fan or blower which is used to conduct ambient air over the external condenser of the air conditioning unit. Thus there is provided a ventilation damper which automatically permits the entry of outside air into the area when the air conditioner is operating and automatically prevents the entry of outside air when it is inoperative.

United States Patent [191 Marsteller VENTILATION DAMPER FOR AIR CONDITIONING APPARATUS [75] Inventor: Kenneth E. Marsteller, Willow Grove, Pa.

[73] Assignee: International Telephone and Telegraph Corporation, Nutley, NJ.

[ 3,826,105 July 30, 1974 7/1963 Pratt 98/l l6 ll/l969 Myers 98/] I6 57 ABSTRACT A ventilation damper for a unitary air conditioner wherein a partition separates the area to be cooled from ambient. An interconnecting aperture in the partition permits outside air to be conveyed into the area to be cooled. A damper mechanism or door normally closing the aperture opens in operative response to a flow of external air produced by a fan or blower. The air flow may be provided by the same fan or blower which is used to conduct ambient air over the external condenser of the air conditioning unit. Thus there is provided a ventilation damper which automatically permits the entry of outside air into the area when the air conditioner is operating and automatically prevents the entry of outside air when it is inoperative.

11 Claims, 6 Drawing Figures [22] Filed: Apr. 19, 1973 .[21] Appl. No.: 352,754

[52] US. Cl.... 62/262, 62/97, 62/186, 62/427, 98/94, 98/116 [51] Int. Cl. F25d 23/12 [58] Field of Search 62/97, 122, 262, 427; 98/94, 94 AC, 116

[56] References Cited UNITED STATES PATENTS 2,l9l,774 2/l940 Reed 98/116 2,535,775 l2/l950 Ashley 62/427 2,634,519 3/1953 Sprouse 98/l l6 2,784,66l 3/1957 Jenn 98/] I6 EVAPORATOR cooL/NG u/v/r E CONTROL PA N61.

VENTILATION DAMPER FOR AIR CONDITIONING APPARATUS BACKGROUND OF THE INVENTION The present invention relates generally to selfcontained unitary air conditioning apparatus of the thru-wall or window mount type. More particularly, it relates to an automatic damper mechanism intended to permit or prevent the introduction of outside ambient air into the interior to be cooled. While the invention may be subject to a wide range of applications, it is particularly suited for use in a unitary air conditioning system and, therefore, is particularly described in that connection.

Self-contained or unitary airconditioning apparatus or room air conditioners are usually provided with two heat exchangers, one located within an inner compartment of the unit and exposed to-indoor air and the other located in an outer compartment exposed to outdoor air. The two compartments are normally separated by a partition which isolates the outside working equipment of the unit from the indoor cooling devices. A pair of fans may provide circulation of the indoor air about the cooling heat exchanger and outdoor air about the external equipment and the condenser heat exchanger. Many of these units are capable of reversal, i.e., for heating or cooling the air within the temperature controlled internal area. The present invention is equally applicable to either mode of operation.

It is often desirable in the operation of unitary air conditioners to allow the introduction of outside ambient air into the interior of the room. To achieve this purpose, a damper or door is provided which either closes or opens an aperture in the partition. Upon opening, outside or fresh air is permitted to mix with the circulating interior air thus affording means for freshening the air often somewhat stale under continued use of air conditioning apparatus.

Prior art approaches to this ventilation mode of operation have fallen into two main categories. The first involves operator control of either a manual linkage or electrical switch located on the front panel of the unit. The manual linkage, of course, simply provides means for opening or shutting the aperture. A disadvantage associated with this simple yet positive way of ventilation is the control is frequently left in the open position thus permitting the entry of outside air when the unit is inoperative or otherwise undesirable. Use of a remote electrical control switch on the front panel and associated ancillary equipment overcomes this disadvantage but significantly adds to the cost of the unit as well as potentially decreasing its reliability.

A second approach to the problem of controlled ventilation is selection through a hidden switch of either no ventilation or continuous ventilation when the unit is in operation. This approach is, of course, similar to the use of a remote electrical control switch and therefore significantly adds to the cost of the unit as well as detracting from its reliability. It is the purpose, therefore, of the present invention to obviate these difficulties and provide an improved ventilation system which normally automatically provides ventilation when desired by the operator.

An object of the present invention is to provide an improved automatic ventilation damper for air conditioning equipment. Another object of the present invention is to provide a simple, highly reliable automatic ventilation damper. Still another object of the present invention is to provide an automatic ventilation damper which is operable only when the air conditioning unit is functioning.

ln accomplishment of the above set forth advantages and objects, the present invention contemplates a ventilation damper for a unitary air conditioner in which a partition separatesan interior temperature controlled area from ambient or outside environmental conditions. The partition has an aperture therethrough which permits the introduction of outside air into the interior thus providing a source of fresh air during operation of the air conditioning unit. A damper mechanism which normally closes this aperture, opens in operative response to a flow of air such as outside air thereby permitting passage of outside air through the aperture. The flow of air is produced by any suitable means associated with the air conditioning unit. I

In one form of the invention, the ventilation damper mechanism comprises a door member which is resiliently or otherwise urged to a closed position. This member includes an air vane extending into the air flow path which in response to the velocity and static pressure of the air stream assumes an open position unless locked in the closed position by operator choice. In a modification of this embodiment, the vane and the door member are resiliently linked. This arrangement provides retraction of the vane from the air stream if the door member is locked in the closed position. The same forces which produce the opening of the aperture act upon the vane to cause its retraction from the air flow. Yet another aspect of the Applicant's invention involves'the use of a pressure sensitive device as the means for resiliently urging the door member toward its closed position. This takes advantage ofthe force produced by the positive pressure of the air stream in effecting an opening of the door member.

For a better understanding of the present invention, together with other and further objects thereof, reference is had to the following description, taken in connection with the accompanying drawings. Its scope is pointed out in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a schematic plan view of a typical air conditioning unit;

FIG. 2 is an amplified schematic of that portion of an air conditioning unit containing one embodiment of the damper mechanism;

FIG. 3 is a plan view of the schematic of an alternative embodiment for the damper mechanism;

FIG. 4 is a schematic plan view of an alternative embodiment of the damper mechanism;

FIG. 5 is a schematic plan view of an alternative embodiment of the damper mechanism; and

FIG. 6 is a perspective view of the door member and vane of the damper mechanism.

The drawings are intended to be illustrative of the present invention and in no way delimiting of its scope. Conventional symbols are used throughout and similar parts are identified by the same number in the various views.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, there is shown a unitary air conditioner which is arranged to be positioned within an opening in an enclosure or internal area. The casing of air conditioning unit 9 houses a fan 12, a compressor 13 and a condenser 14, which equipment is separated from a control panel 23 and cooling unit 15 by means of a partition or barrier 21 as well as the wall 25 of the interior area. The remaining operating parts of the air conditioner are well known to those of ordinary skill in the art and not needed to provide an understanding of the present invention.

To provide communication between the outside or ambient air and the internal area air circulation, aperture 22 is placed in partition 21. A damper mechanism or door 17 is mounted on partition 21 by means of a hinge 18 in juxtaposition to aperture 22. When in normal position, door member 17 of the damper mechanism closes aperture 22 preventing any circulation or passage of outside ambient air into the interior area. Fixedly connected to door member 17 is vane member 16 which extends from partition 21 into air flow 11. Spring member 19 is interposed between vane 16 and partition 21 urging the entire damper mechanism to place door member 17 in a closed position. Thus, when vane 16 is free from any external forces, spring 19 places door member 17 in a position closing aperture 22. It should be noted that by proper arrangement of the door hinging, gravity can be used as the closing force rather than a spring, etc.

On control panel 23 there is slidably mounted a locking mechanism 24. When door member 17 is in a closed position against terminal abutment 28 of partition 21, a strut extending from door member 17 coacts with looking member 24 to prevent opening of door member 17. This is achieved when the operator manually slides locking member 24 into engagement with strut 20. Y

Fan 12, comprising a blower or other means suitable for producing a desired flow of air, moves outside or ambient air 11, indicated by arrows. about the exterior or outside compartment of air conditioning unit 9. Air flow 11 is principally directed about the compressor and the condenser, producing a cooler and more efficient operation of the unit. Operation of compressor 13 and condenser 14 is well known to those of ordinary skill in the art and need not be further explained for the purpose of the present invention. In normal operating conditions, it is frequently desired that a portion of the air flow 11 be introduced into the cooling unit 15 and mixed with air circulating throughout the area to be cooled or temperature controlled. To this purpose, it is necessary that the damper mechanism, principally door member 17, be moved to open aperture 22 in partition 21 thereby permitting the passage of outside air.

Assuming locking mechanism 24 is slidably retracted from engagement with strut 20, the velocity head of air flow 11 produces a force on vane 16. This resultant force overcomes the'resilient urging of spring 19 and allows the damper mechanism to rotate about its hinge 18 retracting door member 17 to an open position. As door member 17 opens, an air flow is produced from the outside of the air conditioning unit to its interior cooling unit 15.

FIG. 6 shows door member 17 and vane 16. The relative cross-sectional areas of vane 16 and door member 17 must be selected so as to provide sufficient opening force and desired aperture 22 dimensioning. Selection of such design parameters is well within the knowledge of those of ordinary skill in the art once the design and bodiment of the present inventiondisplaying an altered positioning of locking member 24. In this instance,

rather than being placed on the control panel of the unit, locking member 24 is introduced through partition 29 and when slidably inserted through partition 29, engages vane 16 causing door member 17 to assume a locked or closed position against terminal abutment 28.

FIG. 3 shows yet another alternative embodiment of the damper mechanism which is particularly suitablefor those applications where the unit may be operated with aperture 22 closed. With aperture 22 closed, vane 16 must interfere with and to some extent decrease the total air flow through the outside compartment of air conditioner 9. This may ultimately result in diminished performance and life of compressor 13 and condenser 14. To obviate this, vane 16 is resiliently linked to door member 17 rather than fixedly connected or integrally formed. A spring member 26 biases vane 16 and door member 17 toward a desired angular displacement. With door member 17 locked in its position against terminal abutment 28 by locking member 24, air stream 1 l impinges on vane 16 causing its retraction from the air stream by overcoming the resilient force of spring member 26. The selection of the desired spring constant is based upon performance criteria of the unit.

FIG. 4 demonstrates yet another design approach to the present invention intended to enhance the operation of the damper mechanism by utilizing pressure differential means for producing additional opening forces. In this embodiment, a second aperture 27 is placed in partition 29 in an area or region contiguous with that portion of vane 16 not subject to air flow ll. Orifice 27 causes an increase in the air flow about vane 16 resulting in the generation of a greater opening force due to an increase in velocity head. Moreover, when aperture 27 is selected to have an appropriate cross-sectional area, there is developed in the region of vane 16 a pressured differential between the positive pressure generated by fan 12 and the ambient or environmental atmospheric pressure. This pressure differential generates an additional static pressure force on vane 16 similarly urging it in the direction of aperture 27 and concomitantly in a direction opening door member 17.

In yet another embodiment of the present invention, FIG. 5 shows a modification of the design disclosed and described in FIG. 4. In this instance, a bellows member 30 is placed in sealed contact with the periphery of aperture 27 and the rear of vane 16. Bellows 30 in addition to providing the spring force urging door member 17 toward a closed position generates an opening force due to a difference between atmospheric pressure and the positive pressure head developed by the actionof fan 12. In this design, the opening force developed by the pressure differential may be easily varied by the sizing of bellows 30. Obviously, as the cross-sectional area of bellows 30 is increased, the total differential pressure force acting on vane 16 is increased. Thus, the design of FIG. 5 permits the generation of two opening forces, one due to the velocity head of the air 11 impinging on vane 16 and the second as a result of the differential pressure developed in bellows 30. The resultant force provides more positive opening of door member 17 which is, of course, a desirable condition in the operation of an automatic ventilation damper mechanism.

It is clear that the present invention provides means for the automatic entry of outside air through selfcontained airconditioning unit 9. Partition 21 separating the area to be temperature controlled has an interconnecting aperture 22 for the passage of outside air. A damper mechanism normally closing aperture 22 is responsive to an outside air flow 11 opening aperture 22 whenever air conditioning unit 9 is operative. The force necessary to displacement or retraction of the damper mechanism from the aperture is provided by a vane'l6 disposed in the air flow thereby providing a positive and continuous opening of door member 17 as long as normal operating conditions are maintained. A locking mechanism 24 is provided to prevent automatic operation of the damper mechanism depending upon operator choice.

While there has been described what are at present considered to be preferred embodiments of the present invention, it will be obvious to those'skilled in the art that various changes and modifications may be made, without departing from the invention. It is therefore intended in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

1 claim:

1. A ventilation damper for a unitary air conditioner comprising, in combination:

a partition separating an area to be temperature con trolled from ambient conditions, said partition having an aperture for passage of outside air into said area;

means for producing a flow of air;

a damper mechanism formed and arranged for normally closing said aperture and for opening in a direction against the flow of outside air into said area; and

means associated with said damper and responsive to said flow for opening said damper thereby allowing passage of said outside air into said area only when said means produces the flow of air.

2. A ventilation damper for a unitary air conditioner comprising in combination:

a partition separating an area to be temperature controlled from ambient conditions, said partition having an aperture for passage of outside air into said area;

means for producing a flow of air;

a damper mechanism having a door member normally urged to close said aperture and a vane operatively associated with said doorand extending into said flow for causing said door member to open when said unitary air conditioner is operating.

3. The damper of claim 2, wherein said door member is resiliently urged toward a closed position by a spring member; and wherein said flow is outside air in a region contiguous with said aperture.

4. The damper of claim 2, wherein said door member is urged toward a closed position by gravity.

5. The damper of claim 3, wherein said door member and said vane are fixedly connected and hingedly mounted to said partition.

6. The damper of claim 3, wherein said door member and said vane are rotatably connected having biasing means interposed therebetween so as to permit resiliently retarded angular displacement of said vane with respect to said door member to retract said vane from said flow.

7. The damper of claim 3, wherein a second aperture is provided in the region of said vane for exhausting to ambient a portion of the air flow from a space behind the vane thereby preventing a pressure build-up and developing an increased force directing said damper mechanism toward an open position.

8. The damper of claim 3, wherein differential pres-' sure means generates a force for opening said damper mechanism when said ambient condition static pressure is less than said flow static pressure.

9. The damper of claim 8, wherein a second aperture and said vane are connected by a sealed bellows to generate a differential pressure force tending to open said door member.

10. The damper of claim 5, wherein locking means actuatable from said area prevents said damper mechanism from opening said aperture.

11. The damper of claim 10, wherein said flow is produced by a fan generating said flow of outside air to enhance the transmission of heat from a compressor and condenser located in said unitary air conditioner. 

1. A ventilation damper for a unitary air conditioner comprising, in combination: a partition separating an area to be temperature controlled from ambient conditions, said partition having an aperture for passage of outside air into said area; means for producing a flow of air; a damper mechanism formed and arranged for normally closing said aperture and for opening in a direction against the flow of outside air into said area; and means associated with said damper and responsive to said flow for opening said damper thereby allowing passage of said outside air into said area only when said means produces the flow of air.
 2. A ventilation damper for a unitary air conditioner comprising in combination: a partition separating an area to be temperature controlled from ambient conditions, said partition having an aperture for passage of outside air into said area; means for producing a flow of air; a damper mechanism having a door member normally urged to close said aperture and a vane operatively associated with said door and extending into said flow for causing said door member to open when said unitary air conditioner is operating.
 3. The damper of claim 2, wherein said door member is resiliently urged toward a closed position by a spring member; and wherein said flow is outside air in a region contiguous with said aperture.
 4. The damper of claim 2, wherein said door member is urged toward a closed position by gravity.
 5. The damper of claim 3, wherein said door member and said vane are fixedly connected and hingedly mounted to said partition.
 6. The damper of claim 3, wherein said door member and said vane are rotatably connected having biasing means interposed therebetween so as to permit resiliently retarded angular displacement of said vane with respect to said door member to retract said vane from said flow.
 7. The damper of claim 3, wherein a second aperture is provided in the region of said vane for exhausting to ambient a portion of the air flow from a space behind the vane thereby preventing a pressure build-up and developing an increased force directing said damper mechanism toward an open position.
 8. The damper of claim 3, wherein differential pressure means generates a force for opening said damper mechanism when said ambient condition static pressure is less than said flow static pressure.
 9. The damper of claim 8, wherein a second aperture and said vane are connected by a sealed bellows to generate a differential pressure force tending to open said door member.
 10. The damper of claim 5, wherein locking means actuatable from said area prevents said damper mechanism from opening said aperture.
 11. The damper of claim 10, wherein said flow is produced by a fan generating said flow of outside air to enhance the transmission of heat from a compressor and condenser located in said unitary air conditioner. 